As known, the use of a screwdriver to manually tighten a screw into an object is time-consuming and labor-intensive. Recently, the cooperation of an electric screwdriver and a screwdriver bit is gradually adopted to achieve time-saving and labor-saving efficacy. However, most of the conventional electric screwdrivers do not have the function of storing and automatically feeding screws. After every screwing operation is performed, the user has to manually take a single screw and attach the screw on a screwing part of the screwdriver bit. In other words, the conventional electric screwdrivers are not user-friendly.
For solving the above drawbacks, a screwing device with a function of storing and automatically feeding screws has been disclosed. FIG. 1 is a schematic side view illustrating a conventional screwing device. The conventional screwing device 1 is disclosed in U.S. Pat. No. 4,998,452. As shown in FIG. 1, the conventional screwing device 1 comprises plural storing portions 10, plural screws 11, a feeding portion 12, a first spring 13, a base 14, a shank 15, a screwdriver bit 16, a tubular body 17, and a second spring 18. The screwdriver bit 16 comprises a first stopping part 161 and a screwing part 162. The tubular body 17 comprises a second stopping part 171 and a third stopping part 172.
For assembling the conventional screwing device 1, the screws 11 are firstly stored in the plural storing portions 10, respectively. Then, the plural storing portions 10 that store the screws 11 are placed on the base 14 within the feeding portion 12. The first spring 13 is arranged between the base 14 and a bottom of the feeding portion 12.
Moreover, the tubular body 17 is connected with the feeding portion 12, the screwdriver bit 16 is disposed within the tubular body 17, and the shank 15 is connected with the first stopping part 161 of the screwdriver bit 16. The screwdriver bit 16 is movable within the tubular body 17 back and forth. Since the first stopping part 161 of the screwdriver bit 16 is stopped by the second stopping part 171 and the third stopping part 172, the screwdriver bit 16 is not detached from the tubular body 17. The second spring 18 is arranged between the first stopping part 161 and the second stopping part 171 for returning the screwdriver bit 16 to its original position.
When the shank 15 and the screwdriver bit 16 are pushed to be moved toward the screw 11, the screwing part 162 is locked into a head part of the screw 11 and a tip of the threaded part of the screw 11 is contacted with a surface of an object. After an electric screwdriver (not shown) connected with the shank 15 is started, the shank 15 drives rotation of the screwdriver bit 16 in order to tighten the screw 11 into the object.
When the electric screwdriver is turned off and the shank 15 is no longer pushed by the user, in response to the elastic force of the second spring 18, the screwdriver bit 16 is moved in the direction away from the screw 11 and the feeding portion 12 until the first stopping part 161 is contacted with the third stopping part 172.
FIG. 2 is a schematic side view illustrating the feeding portion and an ejector of the conventional screwing device. Please refer to FIGS. 1 and 2. The conventional screwing device 1 further comprises an ejector 19 and a third spring 100. The ejector 19 is penetrated through the feeding portion 12 and located beside the topmost storing portion 10. The third spring 100 is arranged around the ejector 19 for returning the ejector 19 to its original position. In case that no screw 11 is stored in the topmost storing portion 10, the user may press the ejector 19 to allow a distal end 191 of the ejector 19 to eject the topmost storing portion 10 out of the feeding portion 12. Under this circumstance, since the number of the storing portions 10 over the base 14 is reduced, the external force applied on the first spring 13 is decreased. Meanwhile, in response to the restoring force of the first spring 13, the base 14 and the remaining storing portions 10 are moved upwardly. Consequently, another storing portion 10 with the screw 11 is located at the topmost position of the feeding portion 12 corresponding to the screwing part 162 of the screwdriver bit 16 again.
As mentioned above, for loading the screws 11 into the conventional screwing device 1, it is necessary to accommodate the screws 11 within the storing portions 10 and then place the storing portions 10 into the feeding portion 12. Moreover, after the topmost storing portion 10 is ejected out by pressing the ejector 19, the subsequent screwing action can be continuously performed by the screwing device 1. In other words, the overall structure is complicated, and the operation is inconvenient.
Therefore, there is a need of providing an improved screwing device and an improved screw supplementary device in order to overcome the above drawbacks.